Nick Reiner denies murdering his parents Rob, Michele in court

Nick Reiner, son of Hollywood director Rob Reiner, has pleaded not guilty to two counts of first-degree murder in the brutal stabbing deaths of his parents.

Both were killed at their home in Los Angeles.

On Monday, February 23, the 32-year-old appeared in the courtroom wearing a brown jail jumpsuit for an arraignment that lasted less than 10 minutes.

Judge Thresea McGonigle announced a preliminary hearing for April 29 to determine whether there is sufficient evidence to proceed with the trial.

Till then, Reiner remains in custody without bail.

The district attorney has charged special circumstances of multiple murders and the use of a deadly weapon for personal use.

If convicted, Reiner could face a life sentence without the possibility of parole or even death, although the prosecution has not yet determined whether to pursue the death sentence.

Following the withdrawal of high-profile attorney Alan Jackson, Deputy Public Defender Kimberly Greene now represents Reiner.

PEOPLE reported that days before killing, Nick and his father had been engaged in a serious argument at O’Brien’s holiday party. At the party, Nick was visibly “freaking everyone out, acting crazy.”

Another prominent aspect of the case is Reiner's mental health conditions, as he was diagnosed with schizophrenia years ago and was taking prescribed medicines, which were adjusted before the killings were reported.